Under display sensors, systems and methods

ABSTRACT

A display device and a method for operating a display device disclosed herein include transmitting a proximity signal from a proximity sensor, the proximity sensor being positioned under a lower surface of a surface layer with an illumination component being positioned between the surface layer and the proximity sensor, in response to the illumination component being deactivated, receiving a reflected proximity signal based on the proximity signal, determining a proximity value based on the reflected proximity signal and modifying an operation of the display device based on the proximity value. The modifying the operation of the display device includes any one or a combination of activating the illumination component, deactivating the illumination component, or modifying a property of the illumination component

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.16/860,198, filed Apr. 28, 2020 which claims the benefit of U.S.provisional Application No. 62/906,039, filed Sep. 25, 2019, which areincorporated by reference as if fully set forth.

FIELD OF INVENTION

The present disclosure relates to sensing devices in general, and moreparticularly, to under display proximity and ambient light sensingmethods, systems and devices.

BACKGROUND

Sensing ambient conditions can be an important part of optimizing theoperation of electronic devices such as devices that include displayscreens. Sensing such conditions can inform the operation of suchelectronic devices so that the electronic devices can operate or beoperated more efficiently and cost effectively.

An electronic device that includes a display screen can also include anumber of additional components that can facilitate use of sensingambient conditions to optimize the operation of the electronic device.The placement and configuration of such additional components canimprove overall performance of the device and reduce manufacturingcosts.

SUMMARY

Techniques, processes, methods, devices, and systems disclosed hereininclude detecting a vertical synchronization (VSYNC) signal cycle,determining a high frequency trigger pulse based on detecting anillumination component's pulse width modulation (PWM) signal, the highfrequency trigger pulse corresponding to the illumination component'sdeactivation times, receiving a delay time period and activating a firstsensor, at a first time, within the VSYNC signal cycle, the first timedetermined based on the high frequency trigger pulse and the delay timeperiod. The first sensor may sense a first sensor reading and may bedeactivated after being activated. A display setting may be adjustedbased at least on the first sensor reading and the illuminationcomponent may be activated after the first sensor is deactivated.According to an implementation, an updated VSYNC signal cycle may bedetermined. Further, a determination may be made that the updated VSYNCsignal cycle is at least one of greater than a high frequency threshold(HFTH) and less than a low frequency threshold (LFTH) and an updatedhigh frequency trigger pulse and an updated delay time period may bedetermined accordingly. The first sensor may be activated at a secondtime within the updated VSYNC signal cycle, the second time determinedbased on the updated high frequency and the updated delay time period.

According to one aspect, a device disclosed herein includes a surfacelayer having an upper surface and a lower surface and formed to receiveambient wavelengths, an illumination component positioned under thelower surface of the surface layer and configured to activate anddeactivate, and a first sensor positioned under the lower surface of thesurface layer such that the illumination component is positioned betweenthe surface layer and the illumination component. The first sensor maybe configured to activate when the illumination component is deactivatedand sense an ambient wavelength emitted through the surface layer whilethe first sensor is activated. A processor is provided and may beconfigured to modify an operation of the illumination component based onthe ambient wavelength sensed by the first sensor.

According to another aspect, a process, method or technique is providedand includes transmitting a proximity signal from a proximity sensor ina reflection effect area of a display device when an illuminationcomponent within the reflection effect area as the illuminationcomponent is deactivated, receiving a reflected proximity signal basedon the transmitted proximity signal, determining that the display deviceis in one of a stable state or a transition state based on the reflectedproximity signal and determining a proximity sensor sensing rate basedon the whether the display device is determined to be in one of a stablestate or a transition state.

According to another aspect, a device disclosed herein includes anillumination component located in a reflection effect area, and aproximity sensor located in the reflection effect area. The proximitysensor may be configured to transmit a proximity signal when theillumination component is deactivated, receive a reflected proximitysignal based on the transmitted proximity signal. A processor may beconfigured to determine that the display device is in one of a stablestate or a transition state based on the reflected proximity signal anddetermine a proximity sensor sensing rate based on the determining thatthe display device is in one of a stable state or a transition state.

According to another aspect, a display device may be manufactured byplacing an illumination component below a surface layer of the displaydevice, and placing a first sensor proximate to the illuminationcomponent. The first sensor may be configured to detect a VSYNC signalcycle, determine a high frequency trigger pulse by detecting a PWMsignal of the illumination component, the high frequency trigger pulsecorresponding to a deactivation time of the illumination component,determine a delay time period and activate at a first time within theVSYNC signal cycle, the first time determined based on the highfrequency trigger pulse and the delay time period.

According to another aspect, a display device may be manufactured byplacing an illumination component below a surface layer of the displaydevice and placing a processor below the surface layer the displaydevice. The processor may be configured to detect a VSYNC signal cycle,determine a high frequency trigger pulse by detecting a PWM signal ofthe illumination component, the high frequency trigger pulsecorresponding to a deactivation time of the illumination component andto determine a delay time period. A first sensor may be placed proximateto the illumination component and may be configured to activate at afirst time within the VSYNC signal cycle, the first time determinedbased on the high frequency trigger pulse and the delay time period.

According to another aspect, a display device may be manufactured byplacing an illumination component in a reflection effect area andplacing a proximity sensor in the reflection effect area. The proximitysensor may be configured to transmit a proximity signal when theillumination component is deactivated and receive a reflected signalbased on the transmitted proximity signal. A processor may be placed inthe display device and may be configured to determine that the displaydevice is in one of a stable state or a transition state based on thereflected signal and determine a proximity sensor sensing rate based onthe determining that the display device is in one of a stable state or atransition state.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described below are for illustration purposes only. Thedrawings are not intended to limit the scope of the present disclosure.Like reference characters shown in the figures designate the same partsin the various embodiments.

FIG. 1 is a system diagram illustrating an example device with adisplay;

FIG. 2A is a cross-sectional diagram illustrating example display andsensors in a device;

FIG. 2B is a cross-sectional diagram including a reflection effect areaof a device;

FIG. 2C is a top view diagram including a reflection effect area of adevice;

FIG. 2D is a top view of illumination components in a display device;

FIG. 3 is a flowchart for activating sensors based on a high frequencytrigger pulse and delay time;

FIG. 4A is a diagram illustrating example sensor activation times;

FIG. 4B is a diagram illustrating an example VSYNC signal;

FIG. 4C is a diagram illustrating an example high frequency triggerpulse signal;

FIG. 4D is a diagram illustrating an example delay signal;

FIG. 4E is a chart illustrating activation times based on a delaysignal;

FIG. 4F is a flowchart for implementing a dynamic variable refresh rate(DVRR) technique;

FIG. 4G is a flow chart for implementing an automatic sync switch timing(ASST) scheme;

FIG. 411 is a diagram illustrating an example ASST schemeimplementation;

FIG. 5A is a diagram illustrating portions of a display device;

FIG. 5B is a diagram illustrating active portions of a display device;

FIG. 6A is an image of states of illumination components and acorresponding pulse width modulation signal;

FIG. 6B is another image of states of illumination components and acorresponding pulse width modulation signal;

FIG. 6C is another image of states of illumination components and acorresponding pulse width modulation signal;

FIG. 7 is an image illustrating an example dark spot on a display;

FIG. 8 is a flowchart for determining display device operation andproximity sensor activation frequency;

FIG. 9A is a diagram of proximity sensor activation times;

FIG. 9B is a diagram of proximity-based states;

FIG. 9C is another diagram of proximity sensor activation times;

FIG. 9D is another diagram of proximity sensor activation times;

FIG. 10 is a diagram of sensor operation modes;

FIG. 11 is a diagram of accumulation functions;

FIG. 12A is a system diagram of sensor activation times;

FIG. 12B is a flowchart for implementing the DVRR technique;

FIG. 12C is a system diagram of the SYNC Generator of FIG. 12implemented in accordance with an ASST scheme;

FIG. 13 diagram of an active-matrix OLED display;

FIG. 14 is a diagram of a sensor package with an emitter and a sensor;and

FIG. 15 is a diagram of a sensor pad.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Embodiments of the present teachings provide techniques, devices, andsystems to implement under device sensing using sensors placed below thesurface layer of a display device such as a mobile phone. The sensorsmay be placed below light emitting components of the display device andmay be configured to sense ambient light wavelengths and/or proximitydetection signals in conjunction with operation of the light emittingcomponents of the display device.

The sensors may be configured to activate while respective lightemitting components of a display device are in an off state such thatlight emitted by the light emitting components that is reflected backinto the display device does not interfere with the operation of thesensors. The off state of such light emitting components may bedetermined by first detecting a Vertical Sync (VSYNC) cycle of the lightemitting components which indicates the cycle refresh rate of the lightemitting components. A high frequency trigger pulse rate may bedetermined based on the VSYNC cycle and a pulse width modulation rate ofthe light emitting components. The high frequency trigger pulse rate mayprovide a trigger pulse to one or more sensors, based on the on and offtimes of the light emitting components within a given VSYNC cycle. Adelay time may also be determined based on the physical location of thelight emitting components and may be applied to the VSYNC cycle to alignthe high frequency trigger pulse rate for each sensor or group ofsensors. The delay adjusted high frequency trigger pulse rate mayprovide the trigger pulse to a sensor or group of sensors such that thesensor or group of sensors is activated at times when the correspondinglight emitting components are deactivated.

According to an embodiment of the present teachings, proximity sensorsmay be activated during off times of corresponding light emittingcomponents to prevent or mitigate visible dark spots on a displaydevice. Further, the frequency of activation of the proximity sensorsmay be determined based on whether a given display device is in a stablestate or an transition state. The stable state and transition states maybe determined based on the proximity of the display device to anexternal object external to the display device.

It will be understood that, although the terms first, second, and thelike may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another. For example, a first element couldbe termed a second element, and, similarly, a second element could betermed a first element, without departing from the scope of the presentteachings. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present. Itwill also be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. It will be understood that these terms areintended to encompass different orientations of the element in additionto any orientation depicted in the figures.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer or region to another element, layer or region asillustrated in the figures. It will be understood that these terms areintended to encompass different orientations of the device in additionto the orientation depicted in the figures.

FIG. 1 is a system diagram illustrating an example device 102 which may,for example, he a smartphone that includes a display which alsofunctions as a touch screen. As shown in FIG. 1 , the device 102 mayinclude a processor 118, a transceiver 120, a transmit/receive element122, a speaker/microphone 124, a keypad 126, a display/touchpad 128,non-removable memory 130, removable memory 132, a power source 134, aglobal positioning system (GPS) chipset 136, and/or other peripherals138, among others. It will be appreciated that the device 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the device 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1depicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip. Further, although FIG. 1 shows a single processor 118, multipleprocessors may be provided to implement the subject matter of thepresent teachings.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station over the air interface 116.Although the transmit/receive element 122 is depicted in FIG. 1 as asingle element, the device 102 may include any number oftransmit/receive elements 122.

The processor 118 of the device 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit) The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the device 102, such as on a server, PC or a home computer.

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the device 102. The power source 134 may be any suitabledevice for powering the device 102. For example, the power source 134may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like, or any known power supplyfor such a purpose.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the device 102. In additionto, or in lieu of, the information from the GPS chipset 136, the device102 may receive location information over the air interface 116 from abase station and/or determine its location based on the timing of thesignals being received from two or more nearby base stations.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs and/or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, a Virtual Reality and/or Augmented Reality (VR/AR) device, anactivity tracker, and the like. The peripherals 138 may include one ormore sensors, the sensors may be one or more of a gyroscope, anaccelerometer, a hall effect sensor, a magnetometer, an orientationsensor, a proximity sensor, a temperature sensor, a time sensor; ageolocation sensor; an altimeter, a light sensor, a touch sensor, amagnetometer, a barometer, a gesture sensor, a biometric sensor, and/ora humidity sensor.

Having described the present teachings in detail, those skilled in theart will appreciate that, given the present disclosure, modificationsmay be made to the present teachings without departing from the spiritof the concepts described herein. Therefore, it is not intended that thescope of the present teachings be limited to the specific embodimentsillustrated and described.

According to embodiments of the present teachings, techniques anddevices for determining under display sensing timing schemes and smartproximity sensing are provided. FIG. 2A shows a diagram of a displaydevice 200 including a surface layer 205 formed to allow ambient lightwavelengths 210 into the display device 200. The display device may bethe same as or similar to the device 102 of FIG. 1 . The display device200 may be any device configured to display and/or otherwise providevisible light via the surface layer 205 and may be, for example, amobile device, a laptop screen, a monitor, a gamming device screen, amedical device screen, or the like. The surface layer 205 may be a fullyor partially transparent layer such that light wavelengths are able toenter and exit the surface layer 205 from both primary surfaces of thesurface layer 205.

The display device 200 may include a light emitting layer 215 which mayinclude a plurality of illumination components 216 configured to emitlight. The illumination components 216 may be Light Emitting Diodes(LEDs), Active-Matrix Organic Light-Emitting Diodes (AMOLEDs), organiclight-emitting diode (OLEDs), or the like. As an example, theillumination components 216 may include components that emit a differentwavelength or range of wavelengths such as those corresponding to red,green, and blue visible light. The light emitting layer 215 includingthe illumination components 216 may be positioned below the surfacelayer 205 within the display device 200. A transistor layer 212 may beprovided and may be positioned below the light emitting layer 215 suchthat the surface layer 205 faces a first surface 215 a of the lightemitting layer 215 and the transistor layer 212 faces a second surface215 b of the light emitting layer 215, such that the first surface 215 ais substantially opposite the second surface 215 b.

Shown in FIG. 2A, the illumination components 216 may produce bothemitted light 216 a and internal light 216 b. Emitted light 216 a may belight produced by illumination components 216 that exits the displaydevice 200 via surface layer 205. Emitted light 216 a may be the lightthat is produced by illumination components 216 to facilitate theintended operation of the display device 200. Internal light 216 b maybe light that is produced by illumination components 216 and isreflected or otherwise directed back into display device 200. Forexample, internal light 216 b may be light that is emitted by theillumination components 216 and is reflected by the surface layer 205and emitted back into the display device 200. Internal light 216 b maybe light that is not provided to facilitate intended operation of thedevice and may be a byproduct of the properties of the light andcomponents of display device 200. Notably, the display device 200 may bearranged such that all or part of the internal light 216 b can beincident upon the one or more sensors in the sensor layer 220, such aslight sensors 230 and/or proximity sensors 240, as further disclosedherein. As applied herein, a light sensor may be an Ambient Light Sensor(ALS), or a similarly functioning sensor known to those in the art.

The transistor layer 212 may include electrical contacts configured toindependently control the illumination components 216. As an example,the transistor layer 212 may include a plurality of thin-filmtransistors (TFTs) which are types of metal-oxide-semiconductorfield-effect transistors MOSFETs. The TFTs may be manufactured bydepositing thin films of an active semiconductor layer as well as adielectric layer and metallic contacts over a supporting substrate. TheTFT layer may be translucent such that light may pass through the TFTlayer and may experience attenuation as it emitted through the TFTlayer. According to an example, the light transmission may be in therange of 5% to 40% due to light attenuation through the TFT layer.

The display device 200 may also include a sensor layer 220 which mayinclude one or more sensors such as light sensors 230 and/or proximitysensors 240, or a combination of those. According to an embodiment, asshown in FIG. 2A, The sensor layer 220 may be positioned below thetransistor layer 212 such that the one or more sensors (e.g., lightsensors 230 and/or proximity sensors 240) face the transistor layer 212and are located on the opposite side of the transistor layer 212 thanthe light emitting layer 215. Accordingly, the transistor layer 212 maybe positioned between the sensor layer 220 and the light emitting layer215. According to another embodiment, the sensor layer 220 may face orotherwise be positioned to detect or sense light emitted from the lightemitting layer 215 without a transistor layer 212 being positionedbetween the light emitting layer 215 and the sensor layer 220. Thetransistors in the transistor layer 212 may be positioned above one ormore sensors in the sensor layer 220 or may be offset from the sensorsin the sensor layer 220 such that the transistors in the transistorlayer 212 are fully or partially offset from the location of the one ormore sensors in the sensor layer 220.

The sensor layer 220 may include one or more different types of sensors,such as light sensors 230 and proximity sensors 240 such that thedifferent types of sensors are positioned on different planes relativeto each other. The sensor layer 220 may be located proximate to or overa printed circuit board 213.

The ambient light wavelengths 210 may be any light wavelengths that aregenerated or otherwise provided external to the display device 200 andthat enter the display device 200 via the surface layer 205. The ambientlight wavelengths 210 may correspond to natural light, externalillumination device generated light, externally reflected light, or thelike, and may be a light that is a combination of light from two or moresources. Notably, the display device 200 may be arranged such thatambient light wavelengths 210 incident up on the display device 200 canenter the display device 200 via the surface layer 205 and can beincident upon the one or more sensors in the sensor layer 220, such aslight sensors 230 and proximity sensors 240.

Light sensors 230 in, or in any way a part of, the sensor layer 220 maybe configured to receive ambient light wavelengths 210 to determine oneor more ambient lighting conditions corresponding to the display device200. The light sensors 230 may receive light wavelengths incident uponthe light sensors 230 and may determine one or more properties of theambient lighting conditions. Such properties may include brightness(LUX), hue, saturation, correlated color temperature (CCT), tristimulusvalues (XYZ or xy), or the like. The light sensors 230 may sense suchone or more properties and generate electric signals that enable aprocessor or other component(s) to modify operation of the displaydevice 200 such as by modifying the operation of the illuminationcomponents 216. The processor and/or other component(s) may beconfigured to operate alone or in conjunction with software, operatingsystem, or the like. Notably, the teachings disclosed herein, includingthose related to FIGS. 2A and 2B may be performed by single components,by a combination of components, and/or by a combination of hardware,software, and/or firmware.

For example, the light sensors 230 may generate electrical signals thatresult in a processor determining that that the ambient light incidentupon light sensors 230 has a brightness value lower than a predeterminedthreshold and, accordingly, the processor may provide an electricalsignal to facilitate reduction of the overall brightness level of lightemitted via illumination components 216.

Proximity sensors 240 in the sensor layer 220 may be configured todetect the proximity of an external object (e.g., the ear of a mobiledevice user), the external object being external to the display device200. The proximity sensors 240 may operate by transmitting a signal at afirst wavelength and sensing a response to the signal as it is reflectedor directed back onto the proximity sensors 240. The signal may be, forexample, an infra-red (IR) signal that is transmitted by one or moreproximity sensors 240 such that the timing, amplitude, and/or phase ofthe response signal that is received as a result of the transmission issensed by one or more of the proximity sensors 240. The proximitysensors 240 may sense the response signal and generate electric signalsthat enable a processor to modify operation of the display device 200such as by modifying the operation of the illumination components 216.For example, the proximity sensors 240 may generate electrical signalsthat result in a processor determining that a user's ear is within athreshold distance of the display device 200 based on the return signalreceived by the proximity sensors 240. Accordingly, the processor mayprovide an electrical signal to facilitate operation of the illuminationcomponents 216, such as, by reducing the output of the illuminationcomponents 216 while the display device is at the user's ear.

As shown in FIG. 2A, both the ambient light wavelengths 210 and theinternal light 216 b may be incident upon the one or more sensors in thesensor layer 220. The ambient light wavelengths 210 may pass through thesurface layer 205 and traverse the display device 200 such that itreaches the one or more sensors in the sensor layer 220 including, forexample, light sensors 230 and proximity sensors 240. The internal light216 b may be or may include portions of the light emitted from theillumination components 216 that is reflected back into the displaydevice 200 by the surface layer 205 or is otherwise directed back intothe display device 200. The internal light 216 b may reach the one ormore sensors in the sensor layer 220 including, for example, lightsensors 230 and proximity sensors 240.

As can be appreciated, light sensors 230 and/or proximity sensors 240may be configured to detect ambient conditions that are external to thedisplay device 200. For example, the light sensors 230 may detectambient light that is incident upon the display device 200 and theproximity sensors 240 may detect the proximity of an external object tothe display device 200. However, operation of the light sensors 230 andthe proximity sensors 240 may produce inaccurate results due to theinternal light 216 b being incident upon the light sensors 230 and/orproximity sensors 240. Notably, while the light sensors 230 areactivated to sense the ambient light wavelengths 210, such sensing mayproduce inaccurate, unintended, or unwanted results when, in addition tothe ambient light wavelengths 210, the light sensors 230 also senseinternal light 216 b. To clarify, such sensing may produce inaccurateresults when detecting ambient conditions because the light sensors 230sense both the ambient light wavelengths 210 and the internal light 216b.

Similarly, proximity sensors 240 may emit a signal (e.g., IR signal) ata given wavelength and may sense the response signal that is reflectedoff an object external to the display device 200. The proximity sensor240 may sense one or more properties of the response signal (e.g.,timing, amplitude, phase, etc.) to determine the proximity of theexternal object. However, the proximity sensors 240 may produceinaccurate results due to the internal light 216 b being incident uponthe proximity sensors 240 in addition the response signals incident uponthe proximity sensors 240.

FIG. 2B shows a different perspective of the display device 200 shown inFIG. 2A. As shown in FIG. 2B, a reflection effect area 250 correspondsto a portion of the surface layer that may reflect light either emittedfrom the light emitting layer 215 towards the sensor layer 220. Toclarify, a portion of the surface layer 205 indicated by the reflectioneffect area 250 may be the portion of the surface layer 205 that canreflect light onto one or more sensors in the sensor layer 220. As shownin FIG. 2B, the ambient light wavelengths 210 may be incident upon thesurface layer 205 and attenuated ambient light wavelengths 210 a whichare an attenuated version of the ambient light wavelengths 210, may beincident upon one or more sensors in the sensor layer 220. FIG. 2C showsa top view of the display device 200 which includes a top view of thereflection effect area 250 that is also shown in FIG. 2B. FIG. 2D showsa top view of illumination components such as illumination components216 of FIG. 2A. The illumination components shown in FIG. 2D may be partof a light emitting layer such as light emitting layer 215. As shown inFIG. 2D, a light emitting layer may include different illuminationcomponents such as green illumination component 261, blue illuminationcomponent 262, and red illumination component 263. Each differentillumination component may be configured to emit light at differentwavelengths and may, for example, have wavelength converting material(e.g., phosphor) that is part of each illumination component.

The components shown in FIG. 2A and 2B are shown to be arranged in anexample arrangement. It will be understood that a modified arrangementof such components may be provided in accordance with the subject matterof this disclosure. For example, the surface layer 205 may be the topmost layer of a display device and the light emitting layer 215,transistor layer 212, and sensor layer 220 may be below, adjacent to,facing, or otherwise proximate to the surface layer 205.

FIG. 13 shows multiple layers of an example display device in accordancewith embodiments of the disclosed subject matter. The example providedin FIG. 13 may correspond to an active matrix OILED with a TFT layerunder the matrix. As shown, FIG. 13 includes a cathode layer 271, anorganic active layer 272, a TFT layer 273, and a substrate layer 274.The TFT layer 273 may include a plurality of TFTs that are configured toindependently address illumination components provided in the organicactive layer 272. The TFTs in the TFT layer 273 may receive signals fromone or more processor and may activate corresponding illuminationcomponents based on the signals received from the one or moreprocessors.

FIGS. 14 and 15 show an example sensor package 280 which includes anemitter window 281, sensor window 282, and a sensor pad 283. The emitterwindow 281 may include or may be located above an IR emitter (e.g., 940nm IR emitter) configured to emit a sensor signal through the emitterwindow 281. The sensor window 282 may be configured to receive a signalreceived as a result of the signal transmitted via sensor window 282.

FIG. 15 shows a detailed view of the sensor pad 283 which includes, forexample, RGB light sensors 285, proximity sensors 286 and bond pads 284.The RGB light sensors 285 and proximity sensors 286 may activate inaccordance with the techniques disclosed herein and may be activatedindependent of each other such that the RGB light sensors 285 areactivated at the same time or at different times than the proximitysensors 286.

According to embodiments of the present teachings, an under displaysensing scheme includes one or more sensors that activate whenillumination components (e.g., illumination components 216 of FIG. 2A)are in an off-state. With reference to FIG. 2A, this under displaysensing scheme allows for one or more sensors in a sensor layer 220 tobe placed underneath the surface layer 205 of a display device 200 suchthat the unwanted effects of internal light 216 b is mitigated orilluminated. The one or more sensors in sensor layer 220 may be placedunderneath the surface layer 205 such that the one or more sensors areon a plane that is below the plane created by the surface layer 205.Notably, the techniques disclosed herein enable operation of one or moresensors in the sensor layer 220 while illumination components 216 areeffectively turned off such that no or minimal internal light 216 b ispresent while the one or more sensors are in operation.

FIG. 3 shows a process 300 for activating under display sensors based onembodiments disclosed herein. Although described with respect to thesystem of FIG. 2A, 2B, 4A, 4B, 4C, 4D, and 4E, those of skill in the artwill recognize that any system, configured to perform the steps ofprocess 300 in any technically feasible order, falls within the scope ofthe present disclosure At step 310 of process 300 of FIG. 3 , a VerticalSync (VSYNC) frequency that indicates the display refresh timing for adisplay device 200 is detected. The VSYNC frequency may be detectedbased on receiving a signal from one or more timing controllers (TCONs)of the light emitting layer 215 shown in FIG. 2 . The VSYNC frequencymay include a rising edge and a falling edge and the time durationbetween a first VSYNC cycle edge (e.g., rising edge or falling edge) anda second VSYNC cycle edge may correspond to the cycle length of therefresh timing for a display device 200. A VSYNC frequency may be anyapplicable frequency that enables operation of a display device and maybe, for example, 60 Hz, 90 Hz, 120 Hz, 240 Hz, or the like. The VSYNCsignal provided by a TCON may be the input to a sync pin of one or moresensors of sensor layer 220.

FIG. 4A shows a diagram that illustrates the process 300. As shown inFIG. 4A, a VSYNC signal 410 may be detected and may have a cycle length411 corresponding to the VSYNC signal 410 frequency. According to thisexample, the VSYNC signal 410 may have a frequency of 60 Hz such thatthe cycle length of each VSYNC signal is .about.16.66 ms. The VSYNCsignal frequency and/or cycle length may be provided by a TCON for lightemitting layer including illumination components (e.g., AMOLED, LED,OLED, etc.). The VSYNC signal 410 cycle length 411 may be measured froma first leading edge to a second leading edge or, alternatively, from afirst falling edge to a second falling edge of the VSYNC signal 410. Theone or more sensors in sensor layer 220 may operate using a driver thatis configured to read a sync cycle detector counter value and maydetermine a VSYNC signal 410.

FIG. 49 shows a simplified portion of the FIG. 4A and includes the VSYNCsignal 410 with cycle length 411. The VSYNC signal 410 may be detectedwhen a corresponding VSYNC detect mode register is set to an enable bit01. The VSYNC signal 410 may be detected using a base clock set at, forexample, 1 MHz. A rising edge 413 may be detected and stored as a risingedge 0 bit at a SYNC_EDGE register corresponding to a sync signal edgesetting. A falling edge 414 may be detected and stored as a falling edge1 bit at the SYNC EDGE register. A frequency detect data register mayinclude 16 bits and may store the VSYNC signal data as further disclosedherein. As shown in FIG. 4B, an illumination component may be activatedone or more (e.g., 4 times in the specific example of FIG. 4B,corresponding to times 422, 423, 424, and 425 as further disclosedherein) within a VSYNC signal 410 cycle length 411.

At step 320 of process 300 of FIG. 3 , a high frequency trigger pulsemay be determined. The high frequency trigger pulse may be based on thedetermination of the VSYNC cycle and may be a high frequency pulse ordigital signal that is provided to the one or more sensors in the sensorlayer 220 of FIG. 2 . The high frequency trigger pulse may be determinedby identifying the pulse width modulation (PWM) driving signal frequency(e.g., 240 Hz) that is generated based on the number of cycles thatillumination components fluctuate between an on and off state within agiven VSYNC cycle. The high frequency trigger pulse may be automaticallydetermined or may be predetermined and may be used to determine thesampling rate for one or more sensors of the sensor layer 220.

FIG. 4A shows an example high frequency trigger pulse 420 described instep 320 of process 300. The high frequency trigger pulse 420 has acycle length 421. Notably, the cycle length of the high frequencytrigger pulse 420 may be, at most, the same as the cycle length 411 ofthe VSYNC signal 410 because the illumination components (e.g.,illumination components 216) can be configured to activate at least onetime within each VSYNC signal 410 cycle length 421. As shown in theexample of FIG. 4A, the cycle length 421 of the high frequency triggerpulse 420 is .about.4.15 ms and the frequency of the high frequencytrigger pulse 420 is 240 Hz and corresponds to a PWM frequency (asfurther described in FIGS. 6A and 6B) of the illumination component(s)based on which the VSYNC signal 410 is determined. Notably, in thisexample, the cycle length 421 of the high frequency trigger pulse 420 isone fourth of the cycle length 411 of the VSYNC signal 410 as the PWMdriving signal frequency for the corresponding illumination componentswould indicate that such components are activated four times within agiven VSYNC signal 410 cycle. As shown in FIG. 4A, an illuminationcomponent may activate at times 422, 423, 424, and 425 which correspondto a frequency that is equivalent to the frequency of the high frequencytrigger pulse 420. The high frequency trigger pulse 420 determinationmay be stored in a high frequency trigger setting register and may beprovided to one or more sensors to determine sensor activation times. Asan example, if the high frequency trigger pulse 420 corresponds to a 240Hz frequency, then the high frequency trigger setting register may store‘4116’ corresponding to a cycle length of 4.166 ms. According to thisexample, a sensor or group of sensors may trigger based on the highfrequency trigger pulse 420 of 4.166 ms resulting in 4 sampling cyclesper 60 Hz VSYNC refresh cycle time 411. As another example, if the highfrequency trigger pulse 420 corresponds to a 120 Hz frequency, then thethen the high frequency trigger setting register may store ‘8332’corresponding to a cycle length of 8.332 ms. According to this example,a sensor or group of sensors may trigger based on the high frequencytrigger pulse 420 of 8.332 ms resulting in 2 sampling cycles per 60 HzVSYNC refresh cycle time 411.

FIG. 4C shows a simplified portion of the FIG. 4A and includes the VSYNCsignal 410 with cycle length 411 and high frequency trigger pulse 420with a cycle length 421. As disclosed herein, the high frequency triggerpulse 420 with a cycle length 421 may be determined based on detecting aPWM corresponding to the activation and deactivation times of anillumination component (e.g., illumination components 216 of FIG. 2A),as further described in FIGS. 6A and 6B. As shown, the high frequencytrigger pulse 420 cycle length 421 may have a duration that is a subsetof the VSYNC signal 410 cycle length 411 as an illumination componentcan have at least one activation and deactivation cycle within eachVSYNC signal 410 cycle length 411, as indicated by a correspondingillumination component PWM signal.

At step 330 of process 300 of FIG. 3 , a delay time is applied to thehigh frequency trigger pulse of step 320. The delay time may correspondto the location of one or more sensors of a sensor layer, such as sensorlayer 220 of FIG. 2 . Notably, the sensor layer 220 may include aplurality of sensors and the sensors may be placed at differentlocations under a light emitting layer 215. The delay time for a givensensor or group of sensors may be determined based on the location,positioning, and/or orientation of the sensor or group of sensors. Thevalue of the delay time may be based on the VSYNC signal and, morespecifically, based on the amount of propagation time it takes for theVSYNC signal to reach the location of one or more sensors. FIG. 5A andFIG. 5B show examples of delay times. As shown in FIG. 5A, a display onthe display device 500 may be segmented into a plurality of rows 501 a,501 b, through 501 n such that the delay time may be based on row timesTime.sub.row-1, Time.sub.row-2, through Time.sub.row-n, for each givenrow. For example, a display pixel driver corresponding to the display ofdisplay device 500 may be subdivided into four or five blocks of gate onarray (GOA) driver circuits. Each GOA driver may drive a specificsection of a pixel line. For example, the display device 500 may includeGOA blocks for the HD OLED display of 2435 pixel lines. As shown in FIG.5B, each GOA driver circuit, 520 a and 520 b, may drive 487 pixel lines.Each pixel line may have a delay time of 8.55 us. According to some GOAimplementations, the sensor location 511 may be placed at a locationsuch that the corresponding pixel line is off during the ending part ofthe VSYNC cycle as shown by RGB sensor on and PS sensor on times 513 aand 513 b that are on towards the end of the corresponding VSYNC cyclewhile the OLED on times 512 a and 512 b are towards the beginning of thecorresponding VSYNC cycle, Alternatively, for example, the pixel line isoff during the beginning part of the VSYNC cycle as shown by RGB on andPS sensor on times 523 a and 523 b that are on towards the beginning ofthe corresponding VSYNC cycle while the OLED on times 522 a and 522 bare towards the beginning of the corresponding VSYNC cycle. The delaytime may be determined during an initial setup stage and may be providedbased on location of each sensor or group of sensors. Notably, the delaytime may be different for each sensor or group of sensors. The delaytime may be less than the cycle length 421 of the high frequency triggerpulse 420.

FIG. 4A shows an example delay time 431 determined based on the locationof the sensor that is activated at times 432, 433, and 434. Notably,application of the delay time 431 may enable the sensor activation times432, 433, and 434 to correspond to times between the illuminationcomponent active times 422, 423, 424, and 425 such that the sensor thatis activated at 432, 433, and 434 is not active while the illuminationcomponent is active. When an illumination component is activated attimes 422, 423, 424, and 425, the light wavelengths produced by theillumination component result in internal light, such as internal light216 b of FIG. 2A. Accordingly, activating a sensor or group of sensorsat sensor activation times 432, 433, and 434 avoids the sensor or groupof sensors from sensing light wavelengths that include such internallight that is produced during times 422, 423, 424, and 425. A delay time431 may be stored in a sensor delay time register and a sensor or groupof sensors may access the sensor delay time register to determine sensoractivation times.

FIG. 4D shows a simplified portion of the FIG. 4A and includes the VSYNCsignal 410 with cycle length 411, high frequency trigger pulse 420 witha cycle length 421, illumination component activation time 422, delaytime 431, and sensor activation time 432. As shown, a delay time 431 maybe determined based on the location of a sensor that is activated attime 432 based on the high frequency trigger pulse 420 with a cyclelength 421 that is determined based on a VSYNC signal 410 with cyclelength 411. The sensor activation time 432 may be a time during which anillumination component is not activated, such as during illuminationdevice activation time 422.

FIG. 4E shows an example sensor time and register bank setting whichincludes IT SYNC values 451 for lighting sensors such as lightingsensors 230 of FIG. 2A, IT_BANK SYNC values 452 for light sensors suchas light sensors 230, IT SYNC values 451 for proximity sensors such asproximity sensors 240 of FIG. 2A, IT_BANK SYNC values 452 for proximitysensors such as proximity sensors 240, The RGB SYNC IT values 451 maydetermine the activation or integration times of a light sensor such aslight sensors 230, where the stepping increase of the activation orintegration is 50 us. As shown in the IT SYNC values 451, the activationor integration time range covers from 500 us to 1.25 ms. The IT_Bankcorresponds to the multiplication factor of the IT SYNC value. Forexample, if IT_SYNC 451 is programmed to 500 us then the IT_Bank value452 of “01” configures the light sensor activation or integration timeto 1000 us. For proximity sensing, an example proximity sensingintegration time is 100 us, The PS IT SYNC value 453 covers proximityintegration time from 50 us to 200 us. For example, if the SYNC IT valueof 453 is programmed to 50 us, then the corresponding IT_Bank value 454of “01” would configure the proximity sensor integration time to 100 us.

Notably, based on the VSYNC signal 410 and the PWM driving signalfrequency's driving timing, a high frequency timing value 421 and asensor delay time 431, as further disclosed herein, are programmed tothe corresponding registers. For instance, if the detected VSYNC signal410 is 60 Hz and the PWM driving timing is 240 Hz, the value of ‘4166’is programmed to the high frequency trigger register. Accordingly, thehigh frequency trigger pule signal 420 is set to a period of 4.166 ms or240 Hz. If a sensor delay time 431 of 3 ms is needed, then the value of‘3000’ may programmed to a RGB delay time register.

According to an implementation of the disclosed subject matter, adisplay device (e.g., display device 200 of FIG. 2A) may support adynamic variable refresh rate (DVRR) such that the display device may beconfigured such that the display device's refresh rate can bedynamically adjusted. For example, the display device may comprise anAMOLD or a microLED display which supports both a 60 Hz a 90 Hz refreshrate. As another example, the display device may be an digital watchwith a microLED display which supports both a 30 Hz and a 60 Hz refreshrate. Such changes in refresh rate may allow for power saving during useof such devices. Alternatively, or in addition, such DVRR capabledevices may allow for enhanced performance when required (e.g., duringoperation of a video game, a higher refresh rate may be implemented).

According to a DVRR based implementation of the disclosed subjectmatter, as further disclosed herein, a change in cycle duration may bedetected during a given cycle. The change in cycle duration correspondsto a modified refresh rate which may be modified based on one or more ofa user setting change, a temperature change, an automatic settingchange, or the like. An automatic setting change may be implementedbased on hardware input, software input, or firmware input and may becaused by, for example, a program or type of program activating on thedevice, a sensor detecting a setting, a capability surplus (e.g.,available device resource bandwidth) or deficit (e.g., constraineddevice resource bandwidth), or the like.

FIG. 4F show a process 470 for a DVRR implementation in accordance withthe subject matter disclosed herein. As shown at step 472 of the process470 of FIG. 4F, a VSYNC cycle detector (e.g., such as VSYNC cycledetector 1210 of FIGS. 12A and 12B, as further disclosed herein) maydetect a display refresh rate (e.g., 30 Hz, 60 Hz, 90 Hz, 120 Hz, 240Hz, etc.). The VSYNC cycle detector may detect the display refresh ratein accordance with the techniques disclosed herein, such as thosedisclosed in step 310 and 320 of process 300 of FIG. 3 and in FIGS.4A-4D.

At step 474 of process 400, the detected display refresh rate may bedetermined to be different than a display refresh rate detected by theVSYNC cycle detector during a previous cycle. The difference in thedetected refresh rates may be greater than a high frequency threshold(HFTH) or a low frequency threshold (LFTH). The FIFTH may be a thresholdamount such that if a detected refresh rate is greater than the previousdetected refresh rate by at least the HFTH, then the process 470continues to step 476 after step 474. Similarly, the LFTH may be athreshold amount such that if the detected refresh rate is less than theprevious refresh rate by at least the LFTH, then the process 470continues to step 476 after step 474. According to an implementation,the FIFTH and the LFTH may be the same value (e.g., 5 Hz).Alternatively, the FIFTH may be different than the LFTH (e.g., the HFTHmay be 5 Hz, and the LFTH may be 7 Hz). According to an implementation,the HFTH and/or the LFTH may be a percentage value (e.g., 3%).

Further, at step 474, based on a determination that a given detecteddisplay refresh rate is different than a previous display refresh rateby at least a HFTH or a LFTH, a variable refresh rate (VRR) interruptflag register may be triggered. The VRR interrupt flag register may betriggered by any applicable technique such as by changing a binary valuefrom a 0 to a 1, by changing a bit value, applying a voltage, or thelike.

According to an implementation of the disclosed subject matter, upon atrigger of the VRR interrupt flag at step 474, a driver may beconfigured to initiate the process 300 of FIG. 3 at step 476 of process470 of FIG. 4F. Notably, upon a trigger of the VRR interrupt flag atstep 474, a VSYNC frequency may be determined (e.g., step 310 of process300 of FIG. 3 ), a high frequency trigger pulse may be determined (e.g.,step 320 of process 300 of FIG. 3 ), a delay time may be applied to thehigh frequency trigger pulse determined (e.g., step 330 of process 300of FIG. 3 ), and one or more sensors may be activated based on the highfrequency trigger pulse and the delay time (e.g., step 340 of process300 of FIG. 3 ).

At step 478 of FIG. 4F, the VRR interrupt flag may be reset such thatthe system may return to step 472. Subsequent changes in refresh ratesthat are greater than a HFTH or LFTH may be detected and the process 470may continue accordingly.

According to an implementation of the disclosed subject matter, anautomatic sync switch timing (ASST) scheme may be implemented. The ASSTscheme may be implemented by applying and/or storing an internalsynchronization signal with an internal synchronization signal cycle,when a VSYNC signal is not actively available. Notably, the internalsynchronization signal may be an initialized signal that is availableprior to the first instance of a VSYNC signal being generated in a givendevice, and/or may be determined based on the last available VSYNCsignal prior to a display device entering an off or sleep state. Theinternal synchronization signal may enable operation in accordance withthe implementations disclosed herein without the use of a softwaresolution, while a display device is entering an idle or sleep state. Toclarify, an idle or sleep state of a display device may correspond towhen the display device is in an idle or battery saving mode, but isstill otherwise powered on. More specifically, the idle or sleep stateis a state when a VSYNC signal is not generated by the display device.

In accordance with an ASST based implementation, the ALS and PStechniques disclosed herein that are generally implemented using a VSYNCsignal may, alternatively, be implemented using the internalsynchronization signal in the absence of the VSYNC signal.

FIG. 4G show a process 480 for an ASST implementation in accordance withthe subject matter disclosed herein. As shown at step 482 of the process480, a display device (e.g., display device 200 of FIGS. 2A-2C) may beinitialized using an internal synchronization signal. The internalsynchronization signal may be pre-programed through physical components,registers, or the like. At step 282, the internal synchronization signalimplemented during initialization may be applied to set ALS/PSparameters. For example, the internal synchronization signal may be usedto determine a high frequency trigger pulse and a delay may be appliedto the determined high frequency trigger pulse such that the ALS and/orPS sensors are activated based on the high frequency trigger pulse anddelay times determined based on the internal synchronization signal.

At step 484, the display device (e.g., display device 200 of FIGS.2A-2C) may generate a VSYNC signal (e.g., if switching to an active oron state). Upon the generation of the VSYNC signal, VSYNC perioddetection maybe activated and the VSYNC signal may be applied, asdisclosed herein. For example, the VSYNC signal may be used to determinea high frequency trigger pulse and a delay may be applied to thedetermined high frequency trigger pulse such that the ALS and/or PSsensors are activated based on the high frequency trigger pulse anddelay times determined based on the VSYNC signal.

Further, at step 486 of process 480, the internal synchronization signalmay be rewritten to materially match the VSYNC signal received at step484. The rewritten internal synchronization signal may be stored suchthat it can be applied at a later time. At a later time, the VSYNCsignal may no longer be available. For example, the display device mayenter a sleep or idle mode due to a threshold period of time elapsingsince use of the display device and/or display screen. At step 488, inthe absence of the VSYNC, the rewritten internal synchronization signal,rewritten at step 486, may be applied to determine the ALS and/or PSparameters, as disclosed herein. The internal synchronization signal maybe applied, as disclosed at step 488, until the VSYNC signal isavailable again. The steps 484 to 488 may repeat during operation of thedisplay device,

FIG. 411 shows a diagram of an ASST implementation 490 in accordancewith the subject matter disclosed herein. As shown, an internalsynchronization signal 491, and/or a VSYNC signal 492 may be used tomake a SYNC decision 493. Prior to an AMOLED panel turning on at time494, the display device is in an internal synchronization mode. Duringthe internal synchronization mode, the SYNC decision 493 is based on theinternal synchronization signal 491. At time 494, a VSYNC signal 495 ais detected and the duration of the cycle of the VSYNC signal isdetermined at time 495 b. Upon the detection of the duration of theVSYNC signal time, the display device switches the SYNC decision 493from the internal synchronization mode to the VSYNC mode, at time 495 b.To clarify, the SYNC decision 493 defaults to the VSYNC signal 492 whenthe VSYNC signal 492 is available and at least one cycle of the VSYYNCsignal 492 has elapsed.

Further, after time 495 b, the internal synchronization signal 491 isrewritten at 495 c, based on the VSYNC period data (e.g., collectedbetween time 495 a and time 495 b). The display device continues tooperate based on the VSYNC data until it is not available. At time 495d, the AMOLED panel is off and the VSYNC signal terminates. After athreshold number of cycles of not detecting the VSYNC signal (e.g, 3cycles, as shown in FIG. 4H), the display device changes back to theinternal synchronization mode at time 496, due to the lack of detectingthe VSYNC signal. Notably, by time 496, the threshold number ofundetected VSYNC cycles may cause the display device to change to theinternal synchronization mode. The display device may switch to an on oractive state at time 497 a such that the VSYNC signal 492 is provided. Afirst cycle length of the VSYNC signal may be detected at time 497 b.The display device may stay in the internal synchronization mode untilthe time 497 b and may switch to the VSYNC mode based on the detectionof the VSYNC signal cycle length at time 497 b. At 498, the VSYNC cyclelength detected at time 497 b may be used to rewrite the internalsynchronization counter.

FIG. 6A shows an image of an illumination component on and off timeswhile a display device, such as display device 200 of FIG. 2A is set toa 90% brightness setting. As shown, times 610 correspond to times whenan illumination component is activated and times 611 correspond to timeswhen the illumination component is deactivated. The PWM signal indicatedby signal line 630 corresponds to approximately a 238.8 Hz signal suchthat the cycle length of the illumination component activation anddeactivation cycle is approximately 4.1 ms and, as shown by timeduration 620, the deactivation time is 575 us. Notably, in this example90% display device brightness setting, the illumination component isactivated for a majority of the illumination activation and deactivationcycle such that a sensor or group of sensors can only be activated for amaximum of 575 us.

FIG. 6B shows another image of an illumination component on and offtimes while a display device, such as display device 200 of FIG. 2A isset to a 50% brightness setting. As shown, times 615 correspond to timeswhen an illumination component is activated and times 616 correspond totimes when the illumination component is deactivated. The PWM signalindicated by signal line 635 corresponds to a similar 238.8 Hz signal asFIG. 6A such that the cycle length of the illumination componentactivation and deactivation cycle is approximately 4.1 ms, However, asshown by time duration 625, the deactivation time for the illuminationcomponent is 1.59 ms which is approximately three times the deactivationtime of the illumination component when the display device is set at 90%brightness, as shown in FIG. 6A. Notably, in this example 50% displaydevice brightness setting, the illumination component is activated for ashorter illumination activation and deactivation cycle when compared tothe activation and deactivation cycle of the device in FIG. 6A, suchthat a sensor or group of sensors can be activated for a maximum of 1.59ms. Accordingly, the lower brightness setting shown in FIG. 6B may allowfor larger sensing times which may result in greater sensing accuracy.

According to an embodiment of the present teachings, the maximum sensingtimes (e.g, that result in sensor activation times 432, 433, 434 of FIG.4A) may be preset to, for example, the duration of deactivation times(e.g., 620 of FIG. 6A and 625 of FIG. 6B) when a given display device isset to a maximum brightness. According to this embodiment, the sensoractivation times will always be at the lowest duration of time when anillumination component is deactivated.

According to another embodiment of the present teachings, the sensingtimes may be dynamic and may be determined based on a given brightnesssetting. According to this embodiment, the sensing times (e.g., thatresult in sensor activation times 432, 433, 434 of FIG. 4A) may be setto 575 us in the example shown in FIG. 6A Where the brightness is set to90% and may be set to 1.59 ms in the example shown in FIG. 6B where thebrightness is set to 50%.

FIG. 6C shows another image of an illumination component on and offtimes while a display device, such as display device 200 of FIG. 2A isset to a 50% brightness setting. The PWM 640 shown in FIG. 2C cyclesonce per corresponding VSYNC cycle such that it exhibits a 50% on and50% off driving scheme.

To summarize the process 300 of FIG. 3 a , as shown in the diagramprovided in FIG. 4A, a VSYNC signal 410 may be provided by a TCON for adisplay device. A cycle length 411 of VSYNC signal 410 may be determinedbased on detecting one or more rising edge and/or falling edge of theVSYNC signal 410. A high frequency trigger pulse 420 may be determinedbased on the VSYNC signal 410 and may be determined based on detecting aPWM signal corresponding to activation and deactivation times of one ormore illumination components. The high frequency trigger pulse 420 mayhave a cycle length 421 which is less than the cycle length 411 of theVSYNC signal 410. The high frequency trigger pulse 420 may split theVSYNC signal 410 and the high frequency trigger pulse 420 cycle lengthmay include a delay 431 and a sensor activation time 432. The delay 431may be determined based on the location of a sensor or group of sensorswhich are activated at sensor activation times 432, 433, and 434. Thedelay 431 may enable the sensor or group of sensors to activate at timesthat are different than illumination component activation times 422,423, 424, and 425 such that the sensor or group of sensors are activatedwhen the illumination component is deactivated. Notably, the sensor orgroup of sensors may be activated at sensor activation times 432, 433,and 434 when internal light reflected based on an illumination componentactivation is not present, such that the corresponding sensor readingsare not affected by such internal light.

As shown in FIG. 2A, one or more light sensors 230 and proximity sensors240 may be provided in a sensor layer 220. A light sensor 230 may beconfigured to sense ambient light wavelengths 210 and may provide theresulting sensed data to a processor. The ambient light wavelengths 210sensed by light sensors 230 may be adulterated if one or moreillumination components 216 are activated at the time when the lightsensors 230 are activated to sense ambient light wavelengths 210.Accordingly, the process 300 of FIG. 3 , as exemplified in FIGS. 4A-4Dprovide a technique that configures a sensor or group of sensors toactive while corresponding illumination components are deactivated.Accordingly, process 300 of FIG. 3 enables light sensors to senseambient light wavelengths 210 without the adulteration effect ofinternal light 216B.

Traditionally, proximity sensors in a display device are not locatedunder the surface layer of a display device as signals emitted by suchproximity sensors interfere with the visible operation of the displaydevice. FIG. 7 shows example results of an image of operating an IRproximity sensor below a surface layer 705 of a display device 700.Operation of an IR proximity sensor can result in visible dark spots,such as dark spot 720 visible on the surface layer 705 of display device700. The dark spot 720 can be the result of activating illuminationcomponents of the display device 700 while also activating the IRproximity sensor, such that the signal emitted by the IR proximitysensor interferes with the light illuminated by illumination components,resulting in the dark spot 720.

The process 300 of FIG. 3 , as exemplified in FIGS. 4A-4D provides atechnique that prevents or mitigates dark spots, such as dark spot 720of FIG. 7 as, according to a proximity sensor is activated whilecorresponding illumination components are deactivated such that theresulting visible effect is void of dark spots.

Additionally, operation of proximity sensors, such as proximity sensors240 of FIG. 2A may be further configured as provided in process 800 ofFIG. 8 .

At step 810, a proximity sensor may be activated. A proximity sensor maybe an IR sensor, upon activation, and may emit an IR signal towards thesurface layer of a display device such that the IR signal or a componentof the IR signal exits the display device via the surface layer. The IRsignal may be emitted by the proximity sensor and may reflect of anexternal surface e.g., if the display device is proximate to a user'sskin when the user places the display device next to the user's earduring a phone call). Alternatively, the IR signal may be emitted by theproximity sensor and may not be incident upon an external object (e.g.,if no external object is proximate to the display device) and, thus, maynot be reflected.

Accordingly, at step 820 of process 800 of FIG. 8 , the proximity sensormay be configured to sense reflected IR signal (e.g., IR reflectionvalues). A reflected IR signal may be received by the proximity sensorand the proximity sensor may be configured to sense a distance betweenthe display device and the external object. The proximity sensor may beconfigured to sense the distance based on one or more of a timing,amplitude, phase and/or the like of the reflected IR signal. Theproximity sensor may provide proximity sensed data to a processor andthe processor may maintain or modify the operation of a display devicebased on the proximity sensed data, as further described herein. At step820, the proximity sensor configured to sense the reflected IR signalmay not sense a reflected IR signal or may sense an reflected IR signalthat is below a given threshold value (e.g., signal amplitude value).The result of step 820 may be a proximity determination which may be,for example, a proximity value (e.g., if a reflected IR signal isreceived) or a null proximity determination.

At step 830 of process 800 of FIG. 8 , a display device operationdetermination may be made based on the result of step 820. The displaydevice operation determination may be made by any component such as, forexample, a processor or a sensor hub device that receives the result ofstep 820. For example, if the proximity value is larger than a HTHvalue, the sensor hub or processor may send a signal that causes thedisplay driver to turn off, reducing the power consumption. According tothis example, the proximity value being greater than the HTH value maycorrespond to the smartphone device being in close proximity of user'shead. Continuing the example, if the proximity value is smaller than anLTH value, then the sensor hub or processor may turn on the displaydriver to resume a normal display screen. According to this example, theproximity value being smaller than the LTH value may correspond to thesmartphone device not being in close proximity of user's head. Thedisplay device operation determination may include, but is not limitedto, activating a display device, deactivating a display device,modifying a property of a display device (e.g., brightness (LUX), hue,saturation, correlated color temperature (CCT), tristimulus values (XYZor xy), etc) or a combination thereof. As an example, the result of step820 when a proximity sensor is configured to sense a reflected IR signalmay be that that the proximity sensors senses an external object withina proximity threshold (e.g., within 6 inches) of the display device.Based on this determination, at step 830, a display device operationdetermination may be made that the display device should ceasedisplaying for at least a given amount of time.

At step 840 of process 800 of FIG. 8 , a proximity sensor activationfrequency may be determined based on the result of step 820. Theproximity sensor activation frequency may maintain a current frequency,increase the frequency, or decrease the frequency of proximity sensoractivation. Notably, decreasing the frequency of proximity sensoractivation may further mitigate or prevent the dark spot effect, asshown in FIG. 7 . The proximity sensor activation frequency may bedetermined based on the result of step 820 such that a given proximityor range of proximities may result in a greater activation frequency anda different proximity or range of proximities may result in a lesseractivation frequency, as further described herein. The determinedproximity sensor activation frequency may be provided as an input tostep 810 such that the proximity sensor may be activated, at asubsequent iteration of step 810, based on the determined frequency andthe process 800 may continue to cycle for the subsequent iteration aswell as additional iterations thereafter.

FIG. 9A shows an example implementation of step 840 of process 800 ofFIG. 8 . As shown, a SYNC signal 910 (e.g., VSYNC signal as describedherein) may be provided and a proximity sensor may be configured toactivate during every alternating cycle of the SYNC signal 910, as shownat signal activation 920. The proximity sensor may be an IR 940 nmemitter and may be provided under a light emitting layer of the displaydevice, such as the proximity sensors 240 of FIG. 2 . As show at signalactivation 920, the proximity sensor is activated once for every twoSYNC signal 910 cycles. Signal activation 930 shows the proximity sensorat a time subsequent to all the signal activation 920. According to theexample shown in FIG. 9A, the result of the proximity sensor activatingat time 930 a by transmitting a signal and sensing a reflected signal(e.g., the result of step 820 of process 800) may be that the proximitysensor determines that the proximity sensor is within 2 inches of anexternal object. According to this example, the proximity threshold maybe 6 inches such that a distance under 6 inches is considered a lowproximity distance. As an example, a user using the correspondingdisplay device may be using the display device to make a phone call suchthat the display device is next to the user's ear. Accordingly, at step830 of process 800, and based on the result of sensing for a reflectedsignal indicating a proximity distance of 2 inches (e.g., the result ofstep 820 of process 800), the display device may temporarily turn offits display to conserve battery life and reduce the heat generated bythe display device. Further, at step 840 of process 800, a determinationmay be made that the proximity sensor activation frequency can bereduced based on the result of sensing the reflected signal anddetermining that the distance is below the proximity threshold.Accordingly, as shown in FIG. 9A, the frequency of signal activation 930may be delayed after the proximity sensor activating at time 930 a suchthat the subsequent that the proximity sensor activates is at time 930 bwhich is four cycles after the previous sensor activation at time 930 a.Notably, the frequency of signal activation 920 for the proximity sensoris twice the frequency of signal activation 930 as a result of theproximity between the sensor and external object being less than theproximity threshold.

According to an embodiment of the present teachings, a high threshold(HTH) and a low threshold (LTH) may be applied to determine a proximitysensor sensing rate. The HTH and/or LTH may be predetermined or may bedynamically determined. A predetermined setting may be preprogrammed ormay be determined based on a user setting or user input. The HTH and/orLTH may be dynamically determined based on historical use, machinelearning, or the like. A proximity sensor sensing rate may be determinedin accordance with FIG. 9B. As shown in FIG. 9B, a HMI may be set to,for example, 2.5 cm and a LTH may be set to, for example 5 cm. Zone 940may correspond to a proximity of closer than 2.5 cm, zone 941 maycorrespond to a proximity between the HTH and the LTH such that theproximity is between 2.5 cm and 5 cm in the example of FIG. 9B. Zone 942may correspond to a proximity of larger than 5 cm.

Zones 940 and 942 may be considered stable zones such that the proximitysensor sensing rate is a slow sensing rate when compared to zone 941which is considered a transition zone where the proximity sensor sensingrate is a high sensing rate as the proximity crosses the region from 941to 940 or from 941 to 942. As an example, stable zone 940, whichcorresponds to a proximity of less than 2.5 cm may correspond to a userplacing a mobile phone next to their ear, such as while on a phone callor may correspond to when the mobile phone is in a user's pocket. Stablezone 942, which corresponds to a proximity of greater than 5 cm maycorrespond to when the mobile phone is placed on a surface and may notbe in use. Transition zone 941, which corresponds to proximity between2.5 cm and 5 cm, may correspond to when a user is holding the mobilephone and may be using the mobile phone. Accordingly, the proximitysensor sensing rate may be low when the mobile phone is in stable zone940 (e.g., while the mobile phone is at a user's ear or in the user'spocket) and stable zone 942 (e.g., while the mobile phone is on asurface). The proximity sensing rate may be high when the mobile phoneis moving from the transition zone 941 into stable zone 940 or when themobile phone is moving from transition zone 941 to stable zone 942(e.g., when mobile phone is on a surface). Although actual proximitydistances (e.g., 2.5 cm and 5 cm) are provided herein, it will beunderstood that proximity may be determined based on the signal strength(e.g., IR reflection value) of a proximity signal, Accordingly, the HTHmay be a smaller value than the LTH such that the signal strength as anobject is further may be lower and such that the signal strength as theobject is closer may be higher.

FIG. 9C shows an example proximity sensor sensing rate when a displaydevice is in a stable zone, such as zone 940 or zone 942 of FIG. 9B. Asshown, the signal activation 944 may occur once every four SYNC cycles943 such that the time gap 945 between each signal activation 944 isfour SYNC cycles, as indicated by the lengths 945A, 945B, and 945 ccorresponding to four SYNC cycles of the SYNC signal 943.

FIG. 9D shows an example proximity sensor sensing rate when a displaydevice is changing from the transition zone 941 to a stable zone such aszone 940 of FIG. 9B, as indicated by duration 965. As an example, aproximity sensor's activation times 951 may include first proximitysensor activation time 951 a. The response from sensing a reflectedsignal based on an IR signal transmitted at the first proximity sensoractivation time 951 a may result in the determination of a proximityvalue that is crossing the HTH (e.g., while the mobile phone is at auser's ear or in the user's pocket) or the crossing the LTH level (e.g.,while the mobile phone is on a surface). Accordingly, the proximitysensing rate may be set to a high frequency such that subsequentproximity sensor activation occurs during the subsequent cycle of SYNCsignal 950, as shown by the second proximity sensor activation time 951b. The proximity sensing rate may continue to be set to a high frequencyfor four cycles of the SYNC signal 950, as indicated by the timeduration 965 which is broken up into 956, 957, 958 and 959 which eachoccupy a SYNC cycle of SYNC signal 950. After the expiration of the fourcycles, a determination may be made that the proximity of the displaydevice is within a stable zone (e.g., zone 940 or 942 of FIG. 9B).Accordingly, the proximity sensing rate may be set to slow frequencysuch that, starting at proximity sensor activation time 952, theproximity sensor activation occurs after four cycles of SYNC signal 950during time durations 966 and 967, corresponding to the signal proximitysensor activation times 952 and 953.

As shown in FIG. 2A, multiple sensors may be provided and may includelight sensors 230 and proximity sensors 240. The multiple sensors may beplaced within the same area occupied by a reflection affect area 250 ofFIG. 2B and 2C. As shown in FIG. 10 , light sensors 230 and proximitysensors 240 may activate relative to each other based on SYNC signal1001. For example, both the light sensors 230 and proximity sensors 240may activate at the same time as shown in operation mode 1010, the lightsensors 230 may activate more often than proximity sensors 240 as shownin operation mode 1020, or the light sensors 230 may activate less oftenthan proximity sensors 240 as shown in operation mode 1030. A givenoperation mode may be determined based on predetermined criteria orbased on dynamically determined criteria, such as based on theattributes sensed by one or more respective sensors (e.g., amount ofambient light or proximity).

According to an embodiment of the present teachings, an accumulationfunction may be applied which may define the frequency of outputtingsensed data. The accumulation function may be applied such that senseddata is output after a set number of sensing cycles, as shown based onaccumulation function 1101 of FIG. 11 , where sensed data is outputafter three sensing cycles at output times 1101 a. Alternatively, theaccumulation function may be applied such that sensed data is outputafter each sensing cycle, as shown based on accumulation function 1102,where sensed data is output after each sensing cycle at output times1102 a. The accumulation function may be predetermined or may bedynamically determined. For example, the accumulation function may beset at a low frequency such that multiple sensing cycles are accumulatedbefore outputting the sensed data (e.g., accumulation function 1101)when a proximity sensor is in a stable zone (e.g., as described in FIG.9B).

FIG. 12A shows a system 1200 which shows an implementation of thepresent teachings. Block 1210 shows a VSYNC cycle detector as describedin step 310 of process 300 of FIG. 3 . A VSYNC input signal 1201 may beprovided by a TCON and may have a frequency of, for example, 60 Hz, 90Hz, 120 Hz, 240 Hz, or the like. The VSYNC input signal may be combinedwith a clock generator 1202 (e.g. 1 MHz clock generator) and may beprovided to a counter 1204 (e.g., 16 bit counter). The counter 1204 mayprovide the clock aligned VSYNC signal to SYNC duty counter 1203 and theclock duty counter 1203 signal may be provided to a counter 1230. Theedge data may be provided to a cycle counter 1223 and an AND gate 1225.The cycle counter 1223 may be a SYNC counter or may be a component ofthe SYNC counter. The cycle counter 1223 may provide the count to aSYNC_Gen counter 1224 which may be configured to determine the durationof a VSYNC input signal 1201 cycle length. The SYNC_GEN Counter may be aSYNC wait signal or may receive a SYNC wait signal. The output of thecycle counter 1223 may be provided to the AND gate 1225 and animplementation of a logical conjunction may be provided to counter 1230.

At block 1220 a high frequency trigger pulse may be generated and mayalso be provided to counter 1230. The VSYNC input signal 1201 may beprovided to a SYNC Edge detector which may detect rising edges (e.g.,rising edges 413 of FIG. 4B) and/or falling edges (e.g., falling edges414 of FIG. 4B) of the VSYNC input signal 1201.

A delay signal 1261 (as described in FIG. 4D) and a duty signal 1262 mayalso be provided to counter 1230. The output of the counter 1230 may beprovided to a sensing mode determination block 1264 which may determinea sensing mode, as described in FIG. 10 based on, for example, logictable 1263. The output of the counter 1230 may be combined with thesensing mode determination block 1264 and may be provided to proximitysensing block 1240 and light sensing block 1250.

Proximity sensing block 1240 may include a PS_Engine 1242 that receivesinputs from the output of the sensing mode determination block 1264,PS_Window 1241 and PS_GAN(IT) 1243. The PS_Engine 1242 may generate andprovide an output to the PS_Counter 1245 which also receives an inputfrom PS_Count 1244 to provide a proximity counter signal which activatesa proximity sensor via PS_OUT 1247. According to an implementation, thePS_Engine 1242, PS_Counter 1245 and PS_OUT 1247 provide inputs to aPS_D_Buffer 1246 which may adjust the timing of the PS_OUT 1247.

Ambient light sensing block 1250 may include an ALS_Engine 1251 thatreceives inputs from the output of the sensing mode determination block1264 and ALS_IT 1252. The ALS_Engine 1251 may generate and provide anoutput to the ALS_Counter 1254 which also receives an input fromALS_Count 1255 to provide a ALS counter signal which activates a lightsensor via ALS_OUT 1256. According to an implementation, the ALS_Engine1251, ALS_Counter 1254 and ALS_OUT 1256 provide inputs to an ALS_DBuffer 1253 which may adjust the timing of the ALS_OUT 1256. The outputsof the PS_Counter 1245 and ALS_Counter 1254 may also be provided to anINT_GEN 1257 which also receives an INT_MODE 1258 signal.

FIG. 12B shows an implementation of the disclosed subject matter thatincludes the DVRR detection technique as disclosed herein. The VSYNCcycle detector 1210 of FIG. 12A may receive a VSYNC input signal 1201from a TCON, at step 1270 of FIG. 12B. The VYSNC input signal 1201 mayhave a refresh rate frequency of, for example, 60 Hz, 90 Hz, 120 Hz, 240Hz, or the like. The detected refresh rate frequency may be provided toblock 1271. At block 1271, the current refresh rate frequency may becompared to a previous cycle's refresh rate frequency. The comparisonmay include determining if the difference between the previous refreshrate frequency and the current refresh rate frequency is greater than aHFTH or LFTH value, as disclosed herein.

If, at block 1271, a determination is made that the difference between aprevious refresh rate frequency and a current refresh rate frequency iseither greater than the HFTH or less than the LFTH, then a VRR interruptflag may be triggered at block 1272. Upon a trigger of the VIM interruptflag, a driver may be configured to determine updated parameters inaccordance with FIGS. 3, 4A-4E. The updated parameters may include, asshown in FIG. 12A, the sync counter 1223 of a sync generator 1220 ofFIG. 12A, the delay signal 1261 of counter 1230, the PS integration time(PS_window) 1241 of proximity sensing block 1240, and the ALSintegration time (ALS_IT) 1252 of ambient light sensing block 1250 andmay correspond to the updated PWM signals that correspond to the updatedrefresh rate frequency, as exemplified in FIGS. 6A-6C. A system registermay be updated based on the updated parameters, as exemplified in FIG.4E.

FIG. 12C shows an implementation of the disclosed subject matter inaccordance with the ASST scheme disclosed herein. Notably, FIG. 12Cshows the SYNC generator of FIG. 12A modified based on the ASST scheme.As shown in FIG. 12C, in addition to the Cycle counter 1223, an internalsynchronization counter 1226 is provided. The internal synchronizationcounter 1226 may generate an initialized signal to be used prior tocomplete activation of a display device. Further, the internalsynchronization counter 1226 may be updated based on the SYNC countersuch that when the SYNC_GEN counter does not provide a signal (e.g.,when the device is in a sleep or idle state), the internalsynchronization counter 1226 can provide the synchronization signalbased on a previous SYNC_GEN counter signal.

As shown in FIG. 12C, the SYNC signal 1201 is provided to AND gate 1225and the internal synchronization counter 1226 signal is provided to ANDgate 1227. When the SYNC signal 1201 is active, SYNC generator outputsthe VSYNC signal 1201 and when SYNC signal 1201 is not active, the SYNCgenerator outputs the signal generated by the internal synchronizationcounter 1226.

As a specific example, the SYNC signal 1201 period detect counter may beimplemented using a 16-bit timing data register (e.g., 1666 us or 60.024Hz). The SYNC signal 1201 period data may be written onto the internalsynchronization counter 1226 when a new SYNC signal 1201 is provided.According to an implementation, a SYNC signal 1201 pulse with of lessthan 10 us may be ignored as noise.

It will be understood that although an IR proximity sensor is describedabove, a proximity sensor may be any applicable type of sensor that isable to detect the proximity of an external object to a display device.For example, the proximity sensor may be a long infrared (LIR) sensor,an ultrasound sensor, a radar sensor, an inductive sensor, a capacitivesensor, a photoelectric sensor, a through-beam sensor, a diffusersensor, an ultrasonic sensor, or any other proximity detection sensor.Accordingly, it will be understood that although an IR proximity sensoris described, the embodiments of the present teachings can apply to anysuch applicable proximity detection sensor.

Those skilled in the art should readily appreciate that the devices,systems and techniques for under display sensing, as defined herein, maybe implemented using any one or more of many available forms,techniques, and components, including but not limited to via nonwriteable storage media such as ROM devices, writeable storage mediasuch as floppy disks, magnetic tapes, CDs, RAM devices, and othermagnetic and optical media, conveyed through wired or wirelesscommunication, through circuits, registers, and the like. The devices,systems and techniques disclosed herein may be implemented in a softwareexecutable by a processor or as a set of instructions embedded in acarrier wave. Alternatively, the devices, systems and techniquesdisclosed herein may be embodied in whole or in part using hardwarecomponents, such as Application Specific Integrated Circuits (ASICs),state machines, controllers or other hardware components or devices, ora combination of hardware, software, and firmware components.

While the present teachings have been particularly shown and describedwith references to embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the scope of the present teachingsencompassed by the appended claims.

What is claimed is:
 1. A method for operating a display device comprising: transmitting a proximity signal from a proximity sensor, the proximity sensor being positioned under a lower surface of a surface layer with an illumination component being positioned between the surface layer and the proximity sensor, in response to the illumination component being deactivated; receiving a reflected proximity signal based on the proximity signal; determining a proximity value based on the reflected proximity signal; and modifying an operation of the display device based on the proximity value.
 2. The method of claim 1, wherein the modifying the operation of the display device includes any one or a combination of activating the illumination component, deactivating the illumination component, or modifying a property of the illumination component.
 3. The method of claim 1, wherein the modifying the operation of the display device is based on comparing the proximity value against one or more threshold values.
 4. The method of claim 3, wherein the modifying includes deactivating the illumination component in response to the proximity value being larger than a high threshold (HTH) value.
 5. The method of claim 3, wherein the modifying includes activating the illumination component in response to the proximity value being smaller than a low threshold (LTH) value.
 6. The method of claim 1, further comprising: determining a proximity sensor sensing rate based on the reflected proximity signal; and modifying a sensing rate of the proximity sensor sensing rate based on the proximity sensor sensing rate.
 7. The method of claim 6, wherein the modifying the sensing rate of the proximity sensor is based on comparing the proximity sensor sensing rate against one or more ranges of proximity values.
 8. The method of claim 6, wherein the modifying the sensing rate of the proximity sensor includes any one of maintaining the sensing rate, increasing the sensing rate, or decreasing the sensing rate.
 9. The method of claim 1, further comprising determining a distance between the display device and an object external to the display device based on the reflected proximity signal.
 10. The method of claim 1, further comprising determining the display device to be in one of a stable state or a transition state based on the reflected proximity signal.
 11. A display device comprising: a surface layer having an upper surface and a lower surface; an illumination component positioned under the lower surface of the surface layer, the illumination component configured to activate and deactivate; a proximity sensor positioned under the lower surface of the surface layer such that the illumination component is positioned between the surface layer and the proximity sensor, the proximity sensor configured to: transmit a proximity signal in response to the illumination component being deactivated; and receive a reflected proximity signal based on the proximity signal; and a processor configured to: determine a proximity value based on the reflected proximity signal; and modify an operation of the display device based on the proximity value.
 12. The display device of claim 11, wherein the modifying the operation of the display device includes any one or a combination of activating the illumination component, deactivating the illumination component, or modifying a property of the illumination component.
 13. The display device of claim 11, wherein the modifying the operation of the display device is based on comparing the proximity value against one or more threshold values.
 14. The display device of claim 13, wherein the modifying includes deactivating the illumination component in response to the proximity value being larger than a high threshold (HTH) value.
 15. The display device of claim 13, wherein the modifying includes activating the illumination component in response to the proximity value being smaller than a low threshold (LTH) value.
 16. The display device of claim 11, wherein the processor is further configured to: determine a proximity sensor sensing rate based on the reflected proximity signal; and modify a sensing rate of the proximity sensor sensing rate based on the proximity sensor sensing rate.
 17. The display device of claim 16, wherein the modifying the sensing rate of the proximity sensor is based on comparing the proximity sensor sensing rate against one or more ranges of proximity values.
 18. The display device of claim 16, wherein the modifying the sensing rate of the proximity sensor includes any one of maintaining the sensing rate, increasing the sensing rate, or decreasing the sensing rate.
 19. The display device of claim 11, wherein the proximity sensor is further configured to determine a distance between the display device and an object external to the display device based on the reflected proximity signal.
 20. The display device of claim 11, wherein the processor is further configured to determine the display device to be in one of a stable state or a transition state based on the reflected proximity signal. 